Biopsies of digestive system organs are commonly indicated in the practice of small animal medicine.

Before the advent of endoscopy, laparoscopy, and ultrasonography in veterinary medicine, the rou­tine method of obtaining tissue samples was by laparotomy. Liver samples were routinely obtained using either blind percutaneous or keyhole biopsy techniques, or wedge or needle samples were pro­cured surgically.

The primary advantage of a surgical approach to organ biopsy is that, depending on the size of the incision, a large area of the digestive organs can be examined and palpated in conjunction with evaluation of other structures (e.g., lymph nodes, kidneys, ureters, prostate). Disadvantages of lapa­rotomy include the invasive nature of the proce­dure when compared with endoscopy, laparoscopy, or ultrasonography; the longer periods of hospital­ization that are required for postoperative recov­ery; and an unwillingness on the part of many owners to subject their pets to any type of major procedure unless “it is really necessary.”

Exploratory laparotomy has and always will be an excellent diagnostic procedure. The use of isoflurane anesthesia combined with our ever­increasing ability to provide better preoperative, intraoperative, and postoperative support for our animal patients, which includes more routine use of effective analgesic agents, has helped make exploratory laparotomy a safer procedure. However, the trend in human medicine over the last 20 years has moved strongly toward using the least invasive methods possible to examine and, when indicated, obtain biopsy samples from abdominal tissues. There has been a similar but more recent trend in veterinary medicine, beginning first in university and specialty practices and now encompassing many smaller practices. It is quite clear that, in situ­ations in which it has been determined that biopsies are necessary, owners prefer and are more likely to allow procedures that are considered less invasive and as causing less overall discomfort to their pet. Indeed, most owners are aware of the tremendous advances in diagnostic technology in the human medical field, and they are often anxious to have these methods utilized in the diagnosis of their pet's disorder.

Endoscopy, laparoscopy, and ultrasonography have many applications in veterinary medicine. As awareness of the tremendous diagnostic potential of these procedures has increased among veterinari­ans, many clinicians are beginning to purchase equipment and learn these new techniques or are more readily making this technology available to their clients on a referral basis. Applications for use of ultrasonography for diagnosis of disorders of the digestive system, as well as many case examples, are presented in Chapter 2. Endoscopy and laparoscopy are discussed in this chapter, with emphasis on the clinical utility of these techniques.